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particle diameters using an alpha-particle imaging detectorMorishita, Yuki; Sagawa, Naoki; Takada, Chie; Momose, Takumaro; Takasaki, Koji
Radiation Protection Dosimetry, 199(13), p.1376 - 1383, 2023/08
Times Cited Count：0 Percentile：0.01(Environmental Sciences)It is very important to evaluate the diameters (activity median aerodynamic diameter) of Plutonium dioxide (PuO) particles for internal exposure dose evaluation. In this study, a method of evaluating PuO particle diameters using an alpha-particle imaging detector was developed. PuO particles with different diameters were modeled by Monte Carlo simulation, and the change in the shape of the energy spectrum for each particle diameter was evaluated. Two different patterns were modeled, namely, the case of 
PuO and the case of PuO (including isotopic composition of Pu). Multiple regression analysis was performed to determine the PuO particle diameter from the obtained parameters. The simulated diameters and the diameters obtained with the regression model were in good agreement. The advantage of using the alpha-particle imaging detector is to measure the alpha energy spectrum for individual particle, and this allows accurate measurement of particle diameter distribution.
-rays after neutron capture by 
La for a T-violation searchOkudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.
EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12
Parity violating effects enhanced by up to 10
times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,) reaction was measured with La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized La target and a 70% polarized 
He spin filter whose thickness is 70 atm
cm are needed. Therefore high quality He spin filter is developed in JAEA. The measurement result of the (n,) reaction at J-PARC and the development status of the He spin filter will be presented.
Takada, Chie; Kurihara, Osamu*; Kanai, Katsuta; Nakagawa, Takahiro; Tsujimura, Norio; Momose, Takumaro
NIRS-M-252, p.3 - 11, 2013/03
A massive earthquake and tsunami on March 11, 2011 resulted in an enormous amount of release of radioactivity to the environment. On the day after the earthquake occurrence, Japan Atomic Energy Agency (JAEA) started emergency radiological monitoring. The measurements with whole body counter (WBC) for the staff members who had returned from Fukushima started at the end of March. The measured activity of 
I due to inhalation for emergency staff varied from LLD to 7 kBq, which corresponded to a range of estimated initial intakes of 
1 to 60 kBq when extrapolated back to the date on which the staff started the operation in Fukushima. The measured activity of 
Cs and 
Cs were both in the ranges of LLD - 3 kBq. The range of initial intake of Cs to I was 11 when taking a median from all the measurements. The maximum committed effective dose of 0.8 mSv was recorded for a worker, a member of the 2nd monitoring team dispatched from March 13 to 14.
I in the thyroids of employees involved in the Fukushima Daiichi Nuclear Power Station accidentKurihara, Osamu*; Kanai, Katsuta; Nakagawa, Takahiro; Takada, Chie; Tsujimura, Norio; Momose, Takumaro; Furuta, Sadaaki
Journal of Nuclear Science and Technology, 50(2), p.122 - 129, 2013/02
Times Cited Count：6 Percentile：43.8(Nuclear Science & Technology)no abstracts in English
Momose, Takumaro; Kurihara, Osamu; Takada, Chie; Furuta, Sadaaki
Proceedings of 1st International Symposium on Radiation Emergency Medicine at Hirosaki University, p.65 - 72, 2010/07
The basic principle of radiation control at plutonium facility such as characteristics of plutonium and relevant radionuclide which are operated in nuclear fuel cycle facilities is introduced and potential radioactive contaminations in accident is discussed. As a practice, decontamination procedure of skin at Tokai Reprocessing Plant, some of the operating principles and applications of various radiation detection and measurement instruments for contamination control and occupational monitoring for internal contamination are introduced. Special methods of measurement for alpha emitters for performing radiological monitoring such as radio autography of plutonium contamination on smear samples, nasal swab sampling and measurement, in vivo and in vitro analysis for plutonium and uranium have been improved and proven. The internal dose calculation code was originally developed in order to estimate retrospectively in case of accidental intake of plutonium.
Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Ito, Kimio; Momose, Takumaro; Miyabe, Kenjiro
Radiation Protection Dosimetry, 127(1-4), p.411 - 414, 2007/11
Times Cited Count：7 Percentile：47.2(Environmental Sciences)Practical action levels for beginning chelation therapy to remove plutonium in the body are now under discussion in Japan since there has been no experience in administrating agents to a subject in accidental intake in Japan although a first commercial reprocessing plant is about to start operation. Recently, International Commission on Radiological Protection (ICRP) proposed some medical intervention levels for chelation therapy on ICRP Publication 96. These levels are determined based on internal dose however common monitoring methods such as lung counting or excreta analysis are not necessarily suitable in terms of both sensitivity and promptness. As an alternative, the authors paid attention to nose swabs and introduced the practical action levels.
Kurihara, Osamu; Hato, Shinji; Kanai, Katsuta; Takada, Chie; Takasaki, Koji; Ito, Kimio; Ikeda, Hiroshi*; Oeda, Mikihiro*; Kurosawa, Naohiro*; Fukutsu, Kumiko*; et al.
Journal of Nuclear Science and Technology, 44(10), p.1337 - 1346, 2007/10
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)In the case of internal contamination of radionuclides, it is necessary to perform internal dose assessment for radiation protection. For this purpose, the ICRP has given the dose coefficients and the retention and excretion rates for various radionuclides. However, these dosimetric quantities are calculated only in typical conditions, therefore, are not necessarily covered enough in the case of dose assessment in which specific information on the incident or/and individual biokinetic characteristics should be taken into account retrospectively. This paper describes a developed PC-based package of software REIDAC to meet the needs in retrospective dose assessment. REIDAC was verified by comparisons with dosimetric quantities given on the ICRP publications and several examples of practical use were also shown.
Tsujimura, Norio; Yoshida, Tadayoshi; Takada, Chie; Momose, Takumaro; Nunomiya, Tomoya*; Aoyama, Kei*
Radiation Protection Dosimetry, 126(1-4), p.261 - 264, 2007/08
Times Cited Count：0 Percentile：0.01(Environmental Sciences)The authors developed a new neutron measuring-instrument that was designed to measure neutron personal dose equivalent, 
(10). This detector is composed a central thermal neutron detector, a core-polyethylene moderator, a front-hemispherical polyethylene moderator and rear-hemispherical boron-contained polyethylene absorber. Dimensions of each part were determined so as to provide energy- and angular-responses close to energy- and angular-dependencies of neutron (10), based on the Monte Carlo calculations.
Am lung monitoring system using an imaging plateHirota, Masahiro*; Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Momose, Takumaro; Deji, Shizuhiko*; Ito, Shigeki*; Saze, Takuya*; Nishizawa, Kunihide*
Health Physics, 93(1), p.28 - 35, 2007/07
Times Cited Count：4 Percentile：31.38(Environmental Sciences)A new Am lung monitoring system without shielding was devised by using an imaging plate system. The Lawrence Livermore National Laboratory's realistic torso phantom containing a Am lung was covered by imaging plates sealed in lightproof bags. The imaging plate system displayed Am lung images characteristic of the lung shape of the torso phantom. The imaging plate system's lower detection limits of 14 Bq for 60 min exposure and 6 Bq for 300 min were the same levels as those of the phoswich detectors and the germanium detectors placed in shielded rooms. The imagingplate system for 60 min exposure detected about 2% of the annual limit of 740 Bq for Am inhalation. A lung monitoring system using imaging plates is applicable for Am lung monitoring.
Tsujimura, Norio; Takada, Chie; Yoshida, Tadayoshi; Momose, Takumaro
Radiation Protection Dosimetry, 125(1-4), p.383 - 386, 2007/07
Times Cited Count：3 Percentile：25.42(Environmental Sciences)no abstracts in English
-UO Mixed Oxide Fuel Fabrication FacilitiesTsujimura, Norio; Takada, Chie; Yoshida, Tadayoshi; Momose, Takumaro
Book of Abstracts, B4/116, p.119, P. 119, 2005/04
None
Pu distribution in the lungHirota, Masahiro; Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Momose, Takumaro; Deji, Shizuhiko*; Ito, Shigeki*; Saze, Takuya*; Nishizawa, Kunihide*
no journal, ,
no abstracts in English
Pu distribution in the lung by an imaging plateHirota, Masahiro; Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Momose, Takumaro; Deji, Shizuhiko*; Ito, Shigeki*; Saze, Takuya*; Nishizawa, Kunihide*
no journal, ,
no abstracts in English
Nakagawa, Takahiro; Takada, Chie; Sekine, Nobuyuki*; Takayasu, Tetsuya*; Tsujimura, Norio; Momose, Takumaro
no journal, ,
no abstracts in English
Kanai, Katsuta; Kurihara, Osamu; Terakado, Yoshinori*; Takada, Chie; Ito, Kimio; Momose, Takumaro
no journal, ,
In JAEA Nuclear Fuel Cycle Engineering Laboratory(JAEA-NFCEL), MOX fuel fabrication facilities and spent fuel reprocessig facilities are operated during over several ten years for the purpose of establishing the nuclear fuel cycle technology. In these facilities, we have to need to pay attention to plutonium. We present the internal monitoring technique for plutonium in JAEA-NFCEL.
Nakagawa, Takahiro; Horikoshi, Yoshinori; Ito, Yasuhisa; Ito, Kimio; Momose, Takumaro; Takada, Chie
no journal, ,
no abstracts in English
Kanai, Katsuta; Kurihara, Osamu*; Takada, Chie; Nakagawa, Takahiro; Morishita, Yuki; Hokama, Tomonori; Takimoto, Misaki; Maruo, Yoshihiro; Momose, Takumaro
no journal, ,
no abstracts in English
Nakagawa, Takahiro; Takada, Chie; Kanai, Katsuta; Murayama, Takashi; Miyauchi, Hideaki; Suzuki, Takehiko; Sato, Yoshitaka; Ezaki, Hiroko; Imahashi, Atsushi; Isozaki, Kohei; et al.
no journal, ,
no abstracts in English
Nakagawa, Takahiro; Takada, Chie; Yamazaki, Takumi; Momose, Takumaro
no journal, ,
no abstracts in English
Takada, Chie; Nakagawa, Takahiro; Yamazaki, Takumi; Ishikawa, Hisashi; Momose, Takumaro
no journal, ,
A special monitoring was performed for the persons working at Central Building in Tokai Reprocessing Plant in September, 2013. One person of the monitored subjects was estimated that he took a tiny amount of radioactive materials accidentally.
